<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>五子棋</title>
    <style>
        body {
            margin: 0;
        }
        .mode {
            margin-top: 15px;
            display: flex;
            justify-content: center;
        }
        button {
            border: none;
            outline: none;
            border-radius: 20px;
            padding: 7px 15px;
            cursor: pointer;
            margin: 0 10px;
            font-size: 17px;
            color: #373737;
        }
        .mode .easy-btn {
            background-color: #D0F3F7;
        }
        .mode .plain-btn {
            background-color: #6BCDDA;
        }
        .mode .hard-btn {
            background-color: #F9957D;
        }
        .mode .reset-btn {
            background-color: #DFEBB7;
        }
        #game {
            background-color: #e9bb87;
            margin: 20px auto;
            border: 1px solid;
            position: relative;
        }
        #game .square {
            float: left;
            border: 2px solid;
            box-sizing: border-box;
        }
        .easy .square {
            width: 70px;
            height: 70px;
        }
        .plain .square {
            width: 55px;
            height: 55px;
        }
        .hard .square {
            width: 40px;
            height: 40px;
            border-width: 1px !important;
        }
        #game .piece {
            position: absolute;
            border-radius: 50%;
            border: 1px solid;
        }
        .easy .piece {
            width: 60px;
            height: 60px;
        }
        .plain .piece {
            width: 45px;
            height: 45px;
        }
        .hard .piece {
            width: 30px;
            height: 30px;
        }
        .black {
            background-color: black;
        }
        .white {
            background-color: white;
        }
        .mask {
            background-color: #333a;
            left: 0;
            top: 0;
            width: 100vw;
            height: 100vh;
            position: fixed;
            display: none;
        }
        .mask .wrapper {
            width: 300px;
            height: 170px;
            background-color: #BCDBA6;
            border-radius: 15px;
            position: absolute;
            left: 50%;
            top: 30%;
            transform: translateX(-50%);
        }
        .mask .wrapper span {
            font-size: 25px;
            display: block;
            margin: 15px auto;
            text-align: center;
        }
        .mask .wrapper button {
            background-color: #66DBFF;
            display: block;
            margin: 70px auto 0;
        }
    </style>
</head>
<body>
    <div class="mode">
        <button class="easy-btn">简单</button>
        <button class="plain-btn">普通</button>
        <button class="hard-btn">困难</button>
        <button class="reset-btn">重新开始</button>
    </div>
    <div id="game"></div>
    <div class="mask">
        <div class="wrapper">
            <span>黑棋胜利</span>
            <button>确定</button>
        </div>
    </div>
    <script src="./index.js" type="module"></script>
</body>
</html>